Characteristics of a Serially Transplanted Mouse Mammary Tumor and Its Tissue-Culture-Adapted Derivative

Abstract

The KHJJ tumor line, derived from a primary mammary tumor arising in a BALB/c mouse after implantation of a hyperplastic alveolar nodule, has been maintained for over 100 transplant generations. The 25th generation of this tumor was grown and selected in cell culture, producing a new tumor cell line, EMT6. This new line can be grown and studied either as an animal tumor or a cell culture and allows the in vitro assay of cell survival after the treatment of animal tumors in situ. Retrospective examination of tumor specimens throughout the history of the tumor lines suggests that these tumor lines were derived from 2 morphologically distinct subpopulations of a mixed primary tumor. The morphology, latent period, and transplantation characteristics (assayed by TD50) of the 2 lines throughout their histories of serial transplantation are described. The antigenicity, growth patterns, and cell population kinetics (analyzed by the percent-labeled mitosis technique and model-based computer analysis) are described for both tumors. Characteristics of EMT6 cells in culture are compared with those of cells in the tumor.